


Substitution

by Yuilhan



Series: Yuilhan's Plot Bunnies [3]
Category: Gokusen - All Media Types, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Crack Treated Seriously, Crossover, F/M, Gen, I think?, Quirkless Character, Substitute Teacher, Tumblr Prompt, inspired by my own headcanon, the crossover no one wanted but I still wrote anyway
Language: English
Status: In-Progress
Published: 2018-11-04
Updated: 2019-06-27
Packaged: 2019-08-17 15:27:22
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 11,135
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16519094
Author URL: https://archiveofourown.org/users/Yuilhan/pseuds/Yuilhan
Summary: In the aftermath of USJ, Aizawa is told to rest. Due to his medical leave, a substitute teacher is needed to take charge of Class 1-A. Enter Yamaguchi Kumiko, and heaven help anyone who threatens her precious students.





	1. Chapter 1

When Class 1-A returned to school after the USJ incident to no current news on the condition of their homeroom teacher, they – rather, those who had witnessed the carnage first-hand – were admittedly worried.

Was their teacher more injured than first believed? Did Eraserhead have to retire from Hero work altogether? If not, who would take over in Aizawa-Sensei’s stead while he recovered? (Because surely all the other teachers had priorities and couldn’t be expected to fill in forever.) Would Aizawa-Sensei even want to still be a Hero after that trauma? Would he by physically and mentally capable to deal with twenty bumbling adolescents?

There were many questions which remained unanswered, despite how frantically students who came across unsuspecting members of Yuuei’s faculty accosted them in the corridors for news. So, Class 1-A settled in behind their desks, and waited upon either the return of Aizawa-Sensei… 

Who were they kidding? The whole room fell into chaos not five minutes after every desk was occupied.

Meanwhile, wheels were in motion. A plan was afoot; one that would temporarily solve Class 1-A's dilemma.

* * *

Yamaguchi Kumiko had been chased out of her last job. It was the third consecutive time it had happened, outside of her leaving other teaching posts to take over where she was wanted most desperately. Usually that mean working with the ‘troubled’ students; the jumped-up little shits who thought they were the (bitter) cream of the crop, and who fought for dominance in a world that had decided not to support them for their indiscretions. Sometimes Kumiko felt more like a nanny than a high school Mathematics teacher, what with how she raised her students from delinquency to maturity.

Kumiko could understand their need for validation, and how eventually, these students gave up fighting for recognition altogether. She had lived in two very separate worlds – often still straddled the fine line between what society deemed acceptable, and the shadier underbelly those in the light often overlooked. Her last foray in teaching had ended rather messily, but quite happily. Kumiko’s students had graduated, she had been fired in the end, but she was happy to be able to watch the boys from Class 3-D find their own ways in the world.

Because _she_ had had a hand in helping them have a better future than the one society had cast them for.

Returning home to her grandfather and the rest of his men, while comforting and familiar, disheartened Kumiko a little. She was a woman in her late twenties, who had devoted her life since graduating from University to her students. Did that make her sad? Most of the women Kumiko was acquainted with (which sadly swung between two extremes; those related to the Ooedo Clan and her work colleagues) had already settled down or had their ten-year plans unfolding before them with mechanical precision. Kumiko had no such plan; she couldn’t even hold down a serious teaching gig for more than three months despite (admittedly in her own opinion) being good at what she did.

“I’m home,” she called, slipping off her shoes and coat by the entry way. Kumiko pulled her glasses from the bridge of her nose, folded the frames, and placed them in her coat pocket ready for the next morning when job-hunting would commence.

Normally this was when Tetsu or Minoru would come scuttling down the hall to greet her. Tonight, there were no such welcoming cheers. Her grandfather hadn’t announced any business on the agenda for tonight, and unease stirred in the pit of Kumiko’s stomach. The house was too quiet for her liking.

“Ojii-San?” Kumiko tread lightly along the wooden flooring, her fingers gently pulling apart the sliding shoji screens that connected the central tatami room from the hall.

Kuroda Ryūichirō did not need rise from his position in the floor to greet his granddaughter; the lightened lines of his wrinkled face, and the knowing twinkle in his eye said it all. “Kumiko! Welcome back.”

Gathered around a kotatsu (in spite of the lateness of spring the days were mild and the evenings positively nippy), Kumiko’s grandfather sat stately; the covers swaddling his knees. Arranged around him in a flanked formation of unity and intimidation, knelt Wakamatsu, Tetsu, and Minoru. Oddly, they were settled on just one side of the table… and on the other, was a rat?

“Am I a rat? Or a bear? Who knows?” Said the mammalian… thing. Had Kumiko spoken aloud? “Yes, but no matter – I get asked the same question quite frequently.”

“My apologies,” Kumiko croaked out, kneeling closer to the kotatsu’s warmth (and the safety of her family).

The rat-bear(?) shook its head. “Excuse me for not introducing myself earlier, I am Nedzu – the Headmaster of Yuuei. So, you’re the infamous ‘Yankumi’ I’ve heard so much about?”

“How came you by that name, Nedzu-San?” Kumiko uttered lowly. She only extended that nickname to her students – even her previous colleagues had insisted on calling her ‘Yamaguchi-Sensei’. Tetsu and Minoru bristled next to her but would make no move unless commanded.

“You might have heard that we had a bit of an incident at Yuuei today,” Nedzu said, paws wrapping around one of the good pieces of earthenware the Kuroda’s owned, which, coincidentally, was only used when a guest was present in the house. “A young man who was aiding the police in their investigation as part of both Yuuei and the students’ legal representation offered me his card, as well as information on your good self in response to a glaring problem we have right now.”

Headmaster Nedzu slid a slip of glossy paper over to Kumiko, who took the business card with intrigue. Printed there in neat black script was the name ‘Sawada Shin’ and all his relevant titles and contact information.

“Sawada-Kun spoke of me?” Kumiko asked incredulously.

“Indeed!” Nedzu squeaked. “We’re currently one teacher short. Normally, I would say our staff could cover, but Aizawa-Kun’s recovery time is indeterminable at this stage. We cannot allow the education of some of our most promising students to slip in the meantime, and frankly, the logistics of organising another timetable is a headache I’d rather not have. At this point, we’re rather desperate, Yamaguchi-Kun.”

“So, you need a substitute?” Drawled the Kuroda elder, drawing Nedzu’s beady gaze from his granddaughter.

Nedzu nodded sharply, rising from the kotatsu. “I do hope you speak with Aizawa-Kun should you accept this position, Yamaguchi-Kun. He has vital information on the students you will be dealing with, though, from what I’ve heard, you’ll settle right in. Please do consider my offer, Kuroda-San.”

Kumiko shared a glance with her grandfather, who in return raised his eyebrows. A faint sense of déjà vu overcame Kumiko; she couldn’t help but feel she had been in this immovable situation (many times) before. Still, accepting the job so happily laid out before her meant she wouldn’t have to search through the classified adds for a bit – and money was money at the end of the day! Plus, maybe it would be interesting to teach at a Hero school for a bit?

“I hope we can get along,” said Kumiko, bowing her head to her new employer.

**Notes for the Chapter:**

> [Inspired by my own hc...](https://yuilhan-writes-things.tumblr.com/post/179754978393/yuilhan-writes-things-yuilhan-writes-things)


	2. Chapter 2

“I said that,” muttered Kumiko as she ambled down the hospital corridor, clutching her bag to her side. “But am I really qualified to take this job?”

She halted only to speak briefly with one nurse; inquiring politely about which room an ‘Aizawa Shota’ was currently residing in. Kumiko was led thirty seconds down the hall –her gym shoes squeaking against the linoleum flooring– where the nurse rapped hesitantly against the door of a private room. 

“He’s a little testy,” said the nurse, running a hand down the back of his neck and dipping his head apologetically. “So far, he’s tried to walk out of the front door no less than four times, and my colleague caught him eyeing up the window underneath his bandages this morning. Heroes really all are the same.”

Aizawa Shota had been determined to return to Yuuei, no matter if the general consensus of his colleagues was that he should remain in hospital and rest up after all he had been through. If he had to tear up the scratchy bed sheets to form impromptu capture gear, then so help him, he would. And if that failed, braiding the flimsy strips together would make a decent enough rope for Shota to scale down the side of the hospital with. There were trees outside, and other patients, so the probability of a soft landing was high. Then he could return to normality, rather than the banal confines of his sterile private room and the bland hospital food. Perhaps, if the nurses had bribed him into staying put with jelly pouches, maybe he would. Or he would have fleeced them and still returned to active duty.

“How do you mean?” Kumiko asked, a bland smile on her face.

The nurse recoiled, blustering their way through a polite answer. “Well, you see, they – um – they ah, they all want to get back on active duty with no concern to their well-being. Hospitalisation over a long term sends them all stir crazy.”

“Like inmates,” Kumiko muttered darkly. The nurse twitched uncomfortably, and swiftly excused himself; throwing a concerned glance over his shoulder as he hurried off to attend to other patients.

Brushing her pigtails back over her shoulder and smoothing down the quilted, padded front of her coat, Kumiko ventured inside the room. Aizawa Shota, still in his undignified backless hospital gown, was trying his best to lower the plastic-coated railings fencing him in on his bed (and struggling rather weakly with his eyes bandaged and one of his arms in plaster).

“Aizawa-Sensei?” Kumiko queried.

The bedraggled invalid stilled. “You’re the one Nedzu spoke of then?”

Kumiko titled her head, noting that he hadn’t answered her directly.

She’d dealt with worse people than Aizawa Shota before. Far worse than a Pro Hero, in fact. The perks of dabbling with the family business, Kumiko supposed, was that you met some absolute bastards when meetings and transactions occurred. Many of the younger families weren’t as strict in their traditions and business as the Ooedo Clan, and the Kuroda-gumi were to be respected for their tenacity and ‘political’ clout alone. The heads of lots of younger Yakuza syndicates were rash, and greedy. They all longed for power and trampled over the fine boundary of respect Kumiko’s grandfather had (rightly) erected in his time – as pseudo Yakuza royalty. And don’t even get her started on _Quirks_.

Quirks were a troublesome thorn in the Kuroda Family’s side, as the majority of their members – and Kumiko’s own lineage – lent themselves to Quirklessness. Generations ago, the police had decided not to tangle with Yakuza politics, seeing as some of the elicit money earned was fed back into the Government and bettered society. These days, (though the Fuzz remained somewhat indifferent) any one with a Quirk, be they Hero, Villain, or fellow Yakuza, could rat you out because they had the power to do so. To cut a very long story short, Kumiko had vindictively taken great delight in putting many a piece of scum back in their rightful place, and if she couldn’t do that through her words alone then her (Quirkless) fists worked just as well. The Yakuza were considered relics of a forgotten age, or small-time thugs playing at villainy. But that did not mean they weren't strong, and organised enough to raise a little hell. 

Kumiko had met many people like Aizawa Shota, and not all of them were the so-called ‘baddies’ society believed could only be manipulative for the sake of evil. No, deviousness was a trait Kumiko had been beholden to; it happened awfully often when she was called in at last minute to teach a class of unruly students. Aizawa Shota, Kumiko could tell, was someone who liked to play mind games. He was someone who was probably very good at getting people tangled up in his own brand of fun. 

Aizawa huffed and rocked uncomfortably on his bed to get comfortable. Obligingly, Kumiko offered to plump his pillows. Though she couldn’t tell from under all the layers of bandages swathing his eyes, it was highly likely Aizawa Shota was glaring at her.

“Nedzu-San was adamant about me speaking with you about this temporary post,” said Kumiko, fluffing his pillows anyway and helping the man sit upright (to which he nonchalantly submitted). She seated herself demurely in an empty visitor’s chair, eyes skimming over the get-well cards lined up on the bedside locker and pasted to the wall with decorative cat-printed tape.

“He seems to think you’re up for the job,” Aizawa replied levelly, with a faint curl of his lips. “Though I myself can’t see why.”

“I suppose that would be the fault of your injuries and wrappings,” Kumiko retorted.

Snorting, Aizawa’s fingers (rather, those not encased in a plaster cast) curled loosely in his lap. “This may work after all. But I’d rather not have to say ‘I told you so’ when you find out for yourself how much of a terror my problem children can be. Who knows if you’ll be able to control them?”

Kumiko knew he was baiting her, but really, that was downright rude. Two could play at that!

“Have you not read my file, Aizawa-Sensei– _oh wait_ ,” Kumiko gasped dramatically and rose suddenly to her feet. “You can’t right now. What a shame, because if not you would have noticed that I’m very experienced in dealing with… _problematic_ students. I have every confidence that we can get along.”

“Good luck with that.” And though he could not watch her leave, Aizawa Shota smirked at Yamaguchi Kumiko’s retreating back.


	3. Chapter 3

Kumiko very much regretted losing her temper and allowing the injured teacher to rile her as instantly as he had, realising as such as soon as she walked out of Aizawa's hospital room. However, the steely posture of her spine, narrowed eyes, and the white-knuckled grip on her bag strap kept her from returning and begging for more information on Class 1-A.

Wouldn’t that be a treat? Teaching an upper set class rather than one of the lower classes – the former had always been reserved for the more ‘experienced’ (read: less steadfast) teachers. Kumiko had often wondered what it was like to teach the 'ideal' students, and now she might finally know. Aizawa had stated his class was full to the brim with ‘problem children’, but really, compared to teenage delinquents how bad could a bunch of Hero-wannabes be?

Kumiko would start at Yuuei the following day, but first she had to return home from Musutafu Central Hospital. Her ID pass had already been mailed to the Kuroda household, as had a thick Manilla folder containing the relevant information, class rosters, paperwork, and the timetable of her duties for a normal working week. The issue with Kumiko’s new employment, however short a term it may be, was that the Kuroda household was quite the distance away from Yuuei’s campus. Nedzu had assured her –and by extension, her grandfather and her overly-protective clan members– that accommodation would be provided at no further cost.

Thus, on the morning of her first day as an interim teacher at Yuuei Academy, Kumiko hugged her family good bye and wheeled her suitcase down the lane to the bus stop. There she caught her ride, walked to the nearest train station, and then sat for a torturous two hours in silence all by herself on the train because it was an ungodly morning hour and punctuality was not one of her strongest suits. She wasn't going to mess up making her first impression at a school full of Heroes though, no matter her background. Her suitcase, within which was about a month’s worth of tightly bundled clothes and necessities, rattled quietly as the train hurtled down the tracks.

Finally arriving at Yuuei’s front gates just shy of seven in the morning, and already feeling exhaustion tug at her senses, Kumiko flashed her identification pass to a discrete monitor just at the campus’ threshold and eased her way to the front entrance.

“Nedzu-San!”

“Good morning, Yamaguchi-Kun,” Nedzu chirruped. He eyed Kumiko’s luggage. “Ah, if you don’t mind I’d like for one of my staff to show you your accommodation this evening once the school day is over. You’re more than welcome to keep your things in the faculty break room however.”

“I hope you don’t mind,” Nedzu continued. “But would you mind keeping your heritage under wraps for now? We try not to discriminate at Yuuei, and I have every confidence that your grandfather and family have raised you to be an upstanding person, but parents and Pros often don’t agree with my policies.”

A little dismayed, Kumiko agreed. It hadn’t been the first time she had been asked to keep the Yakuza thing secret, and obviously now it wouldn’t be the last time either. She felt she should warn Nedzu, however. Sooner or later her secret always slipped out, generally through no fault of her own (unless you saw protecting your students from thugs to be a fault). Something halted her tongue though, and Kumiko swallowed down her words of caution; though she may come to regret that decision later, she was sure.

Kumiko was whisked through the halls –still free of students, and curiously, other teachers– to the staff room, where she deposited her suitcase, then on to the shared offices where most of her work outside of the classroom would be conducted. There, many of the Pro Heroes who doubled as teachers at Yuuei, were already beginning their working day, in the loosest sense.

Though her knowledge was limited, Kumiko could recognise a few of the Heroes present; some from television and the news, others in dealing with the police and knowing who exactly the Kuroda-gumi should avoid, and some through the sole fact that Kumiko had grown up surrounded by men who appreciated the female form maybe a little too much. Midnight was identifiable on sight from the latter alone, and Kumiko couldn’t halt the rising flush in her cheeks at the Pros attire. (She was just as attractive in the flesh -and her costume- as she had been on Tetsu's treasured posters.)

Other than Midnight, who winked cheekily at the blushing substitute, and Present Mic (who’s radio broadcast Kumiko had habituated listening to whilst grading papers and homework), Kumiko knew a limited number of faces there in the room. One was escaping her entirely; the figure of a gaunt blond-haired man in an overly large suit. There was something oddly familiar about the lank drapery of his bangs, or the wide stretching and grim line of his grin. The man diverted his attention from Kumiko back to his papers –shuffling them uncomfortably– and she too looked away.

She’d had strange reactions before, but something about the spindly man set her nerves on edge. What a great start to her morning and her introduction to her colleagues. Unless he knew about Kumiko’s origins and the family ‘business’? Because if her did, then she wasn’t sure she liked how he fidgeted under her scurrility.

“This is Yamaguchi Kumiko.” Nedzu gestured to her, and she dipped into a respectful bow. “She’ll be taking over as Class 1-A’s homeroom teacher until Aizawa-Kun is deemed fit and feels ready for work again.”

Throwing back his head with a hearty raucous of laughter, Present Mic said, “Well, looks like you’ll only be in a job for a few days Yamaguchi-San if Shota has anything to say about it!”

“He gave me that impression as well,” Kumiko admitted, and the Hero laughed again.

“I think we’re going to get a long just fine, Yamaguchi-San – call me Yamada, ‘kay?”

“Me too! Me too!” Midnight, who then introduced herself as Kayama Nemuri, cried. “Let’s get along, ‘Guchi-Chan!”

Startled by the older woman’s familiarity, yet at the same time, strangely flattered, Kumiko blushed prettily and brought a hand to rest against her cheek. “It’s… It’s a little silly, but please call me ‘Yankumi’.”

Kayama’s thumbs up and pleased smile said it all. “Yankumi? I _like_ it – short and sweet, but kinda spunky!”

“’Spunky’,” Kumiko echoed, wide eyed. “Sure.”

She settled at a spare desk and would have thought that maybe she would have temporarily presumed access to Aizawa’s. Still, unlike Kumiko Yuuei’s staff were mainly comprised of Heroes and those who worked with sensitive information constantly. It was likely Kumiko had been granted her own, and fresh, workspace, purely because there were documents she really shouldn't have access to situated at Aizawa’s desk.

She coughed and caught Kayama’s attention. “My apologies, but does the school have anywhere I can change?”


	4. Chapter 4

At eight twenty-five precisely the five-minute warning bell for students hurrying to their homeroom classes sounded. Kumiko saw that as her cue to find her way to 1-A’s classroom. The offices were deserted as she returned, placing her neatly folded clothes in an empty drawer at her desk. She tugged at her pigtails, pulling the hair trapped within the elastic bands taught, then removed her glasses and rubbed the lenses on the sleeve of the red tracksuit she had changed into before perching the frames securely into place again. Kumiko tapped the toes of sneakers against the sterile white office flooring, like a sprinter settling into the blocks, and collected her class register. It was time for her to make her entrance, and to meet her new students.

An explosion shook through the room Kumiko was about to enter. She rested the flat of her palm against the door hesitantly, gulping. She wasn’t scared, not one bit, despite these kids (who had, in terms of power, more than she could ever hope to possess - even more than some of Kumiko’s prior students, notwithstanding all of their bluster) being part of a Heroics course and not your run-of-the-mill delinquents. What could they possibly do to her that she couldn’t handle, outside of using their Quirks on a civilian; the latter of which none of her 3-D boys had even dared to try.

Kumiko was used to living in a Quirked society, where everyone just assumed power without looking deeper or even asking. She’d always been strong, so it was easy to forget just how overlooked the Quirkless were in actuality. These kids were on another level from the changing-hair colour at will, stretchy limbs, and lizard tongued individuals who weren’t deemed strong enough for Hero work.

The final bell rang, and a clatter of chairs being drawn back from desks reached Kumiko’s ears. She took a deep breath. Stretched out the hand that originally rested against the door to 1-A’s classroom.

“Let’s do this. Fight-o, _oh_!” Kumiko whispered encouragingly under her breath, pumping her fist to psyche herself up. Then she shoved back the sliding door and stepped inside.

Instantly the chatter from students ceased. Twenty pairs of eyes surveyed the slight woman clad in an eye-wateringly bright red tracksuit manoeuvre herself behind the lectern where Aizawa generally stood. Some students were internally a little distressed that their homeroom teacher had not returned, though felt silly for thinking that despite healing Quirks present these days that their teacher would be healthy and hale enough to return to his duties.

The corners of Kumiko’s lips twitched in a nervous smile. “Good morning.” She hesitated, eyes flicking to the face of each student.

Kumiko bit her lip and turned the blackboard behind her, finding a stub of chalk with which she wrote her name.

“I am Yamaguchi Kumiko,” she said in a stilted, syllabic manner, sounding out her name as she wrote, “and I’ll be your homeroom teacher until Aizawa-Sensei’s return. I’ll also be helping out during your Mathematics classes. I’m twenty-nine, and coincidentally also single.”

(She could have sworn she heard as someone snorted and muttered ‘Unsurprising’ at the reveal of that last statement.)

Kumiko turned her attention back to her new students. Several appeared to be perched on the edge of their seats, the epitome of concern etched on their faces. One curly green-haired boy looked like he was about to burst into a flood of tears. “Don’t worry about Aizawa-Sensei, you guys. He’s fine, Nedzu-San just wanted him to take further time off to fully recover – that’s why I’m here. Let’s all get along, okay?”

Almost instantly, chatter resounded through the small classroom. Kumiko only just held herself back from rolling her eyes. This always happened whenever she introduced herself, and she should have not be so naïve to think a higher-tier class would be any different from those she normally taught. Aizawa Shota was a figure who commanded respect because you were never sure what he was thinking, and who baffled you into silence with his curious mannerisms and mind games. Yamaguchi Kumiko, looking frumpy in her bright red tracksuit, her pigtails, and old-fashioned oval shaped glasses, did not amount to much in the eyes of Class 1-A.

“Everyone…” she called lightly, hoping the class would settle down. They did not. Irritation crept into Kumiko's tone. “ _Guys_ …”

Still the conversations continued. Kumiko wasn’t sure they were even directed at her anymore – just people taking off from where their chats had abruptly halted when she’d first entered the room. Substitute teachers were often seen as weak or lesser to students who were used to their no-nonsense instructors. Kumiko had experienced the same in her own high school years (which, admittedly at this point in her life, seemed very long ago), but she was never so disrespectful to ignore someone who was taking the time to continue the education of students they weren’t familiar with – someone who had stepped into situations they themselves might not be comfortable in, trying to make the best of it.

Substitute teachers were almost like Heroes, Kumiko mused. They came in to save the day, often at short notice. Students failed to realise that though. To them (or rather, most of the students – a few were watching Kumiko anxiously and hunching down over their desks in mortification), Kumiko was a free pass with which they could goof around and relax; a weak-willed waste of space that the Class 1-A's more boisterous students could walk all over. What a shame it was, then, that Class 1-A’s substitute teacher had a stronger spine than they believed.

“Oi! You guys better shut it!” Kumiko snarled, finally losing her temper and smacking Aizawa's lectern with her palm. It wobbled unsteadily under the force of the blow; the wooden joints splitting apart and splintering. You could have heard a pin drop in the classroom with how quickly the student’s chatting fizzled out. “It’s rude to talk over someone when they’ve got a job to do.”

Kumiko gulped, twiddled with one pigtail nervously, and stuttered out an excuse over how things were made so shoddily these days. She grinned unconvincingly; “I mean… er, um, it’s good that you’re all quiet now, so I can take attendance!”


	5. Chapter 5

“Did you see how she hit that desk?” Uraraka Ochako exclaimed, tugging on Iida Tenya and Midoriya Izuku’s arms as she dragged the two to the cafeteria. It was time for their lunch break, and only now did they have the time to talk about the mysterious substitute.

“She has to be really powerful,” Ochako continued, nearly swallowed up by harried students also joining the lunch-rush queues. “Seriously, she just slapped that desk and ‘Blam!’ it was wobbling!”

“Well, maybe she’s got some sort of strength enhancing Quirk?” Iida suggested. “Though I don’t condone damaging school property – even if it the teacher causing said damage.”

They separated only to wait in line and buy their meals, but soon Ochako, Tenya, and Izuku regrouped at their usual table.

“It wasn’t like any of the strengthening Quirks I’ve seen before – or like mine,” Izuku explained. “Usually there’s some sort of acknowledged enhancement. I usually glow and break my bones, All Might creates huge levels of air pressure with his punches, and some of the Villains I’ve seen enhance their muscles or warp into an heightened form of musculature when their Quirk is active – sort of like how you can tell Aizawa-Sensei is using his Quirk if his hair is floating and his eyes are red. Yankumi-Sensei didn’t have an obvious tell though.”

Dizzied by the explanation (but rolling with it anyway) Ochako and Tenya simply nodded. They’d had a few weeks to get used to Izuku’s tangents, and well, the green-haired teen usually wasn’t too far off the mark.

Izuku snapped his set of disposable chopsticks apart, and gently lifted a helping of rice from his meal set to his lips. He chewed contemplatively, his jaw twitching as though he wished to speak yet constantly remembered it was considered rude to talk with his mouth full in polite company. “If… If Yankumi-Sensei has a strength-enhancing Quirk, for lack of a better term, then it’s one that is constantly active. It might be better to say that it’s more like, um, pure ‘super strength’. She’s always had it there with her, so it’s less about how much power she can put into her blows, but more about negating the power – trying to reduce her strength to a level that is manageable and not likely to cause serious damage. There’s no way of telling what limit her strength has, unless we see her go all out.”

Ochako looked down at the table, hands clenching into fists. “That’s a little sad when you think about it; not being able to do simple things without fearing you’ll break something.”

“Truly, Yamaguchi-Sensei must dedicate herself to training if she can control herself as well as we have seen,” Tenya concluded. “I will admit that perhaps I was rash in my assessment of her behaviour – it is something I am trying to work on.”

“It’s okay, Iida-Kun,” Ochako beamed. “We’re all here to learn. Yankumi-Sensei looked super embarrassed after she raised her voice though, but I guess it was justified.”

Tenya hummed. “Indeed, it was rude of our classmates to talk over her. Perhaps I should speak to them on her behalf about respecting authority figures?”

“I, er, really don’t think that’s necessary.” Izuku winced, picturing Tenya’s hand-chops as he lectured Class 1-A about social queues and respectfulness. He couldn’t imagine it would go down well; Izuku flinched preemptively at Kacchan's reaction to a lecture. “Yankumi-Sensei seemed to have it under control.”

Yamaguchi ‘Yankumi’ Kumiko did not, in fact, have it under control. She fell into the deepest bow she could muster as soon as Headmaster Nedzu walked into the teacher’s break room.

“My deepest apologies, I severely damaged Aizawa-Sensei’s lectern during homeroom this morning,” she blurted out. “I did not intend to do so, but the students weren’t listening so I thought I’d make a bit of noise and gather their attention and, well-“

“Yamaguchi-Kun, raise your head,” Nedzu squeaked tentatively. “You are not the first teacher to have had such an accident happen to them. My, even Hound Dog sometimes isn’t aware he is scratching up the facilities. It’s a by-product of his Quirk to have sharpened claws, and we will always overlook such incidents because they are not occurring out of malice. Though, how did your first introduction to 1-A go?”

“Once I’d taken attendance and they’d settled, they all seem to be bright pupils – though what else could I expect from a Heroics class?” Kumiko smiled gently. “I did have some initial concerns though.”

“Such as?” Nedzu probed.

Kumiko shook her head. “I don’t know whether it’s my place to say anything. I'm only an interim replacement, and Aizawa-Sensei may have already been working on the same problems I am noticing.”

By now, multiple teachers were interested in what Kumiko had to say, and she relented if only to take their eyes off of her for a little while. “There’s a split in the class, but it isn’t very clearly defined. One faction seems to favour Bakugou-Kun as their leader, and the other Midoriya-Kun. Those are the two groups that stood out to me the most, but Midoriya’s lot are the more respectful gang. Then there are wild cards; Todoroki, Yaoyorozu, and the like. They fit into neither group but have powerful Quirks.”

“’gang’?” Midnight, who had insisted Kumiko should call her ‘Kayama’ or ‘Nemuri’ (though Kumiko couldn’t quite bring herself to do as such), echoed.

Kumiko flushed an unsightly shade of red. There was the Yakuza-upbringing creeping into her speech yet again. “Mm,” she hummed. “Gang, group, faction – I, um, don’t really know how to explain it, but there’s definitely two distinct leaders in the class who clash with one another, and on top of that a few wild cards.”

“So, it’s a dominance thing?” Kayama queried, looking genuinely excited for some reason. Present Mic, coffee mug in hand, took one look at his colleague and clamped a hand on her shoulder; pulling the R-rated Hero away from a dithering Kumiko. The latter sighed in relief.

“What is your impression of Midoriya-Shonen?” The raggedy, skeletal teacher Kumiko had met that morning inquired.

“Shy,” Kumiko answered instantly, titling her head as she thought. “Kind, and a little jumpy. There’s an underlying intelligence in his eyes though, and I’m pretty sure he was muttering under his breath about what my Quirk might be when I broke that desk.”

The blonde seemed pacified, but his back stiffened somewhat suspiciously. “Out of curiosity, what is your Quirk?”

Kumiko shrugged. “I guess I’ll never know.”

A vague answer, perhaps, but the only one Yamaguchi Kumiko was going to –and could– give. The scraggly blond’s brows raised minutely – though it was hard to tell under the deep furrows and shadows surrounding his eyes.

“You don’t know what your Quirk is?” He murmured. Kumiko could have cursed; while she wasn’t adverse to people finding about her Quirkless stature, she didn’t necessarily want it bandied about. Life as a Quirkless individual was tough, and with the help of the Kuroda-gumi she had flourished. Others could not claim to be so lucky. “Yamaguchi-San, are you perhaps-“

“I can neither confirm nor deny,” she snapped, figuratively buttoning her lips and resolving to keep to herself for the rest of her lunch break. “It’s quite rude to ask a person about their Quirk, sir. I’d rather keep mine to myself.”

As she passed them, Kumiko could have sworn she heard Nedzu mutter about how she had ‘handled that well’. Kumiko did not feel as though she had, and no words of encouragement from a rat, bear… _thing_ , could bolster her. A pang of homesickness struck Kumiko to her core; her grandfather’s wise words, the combined efforts of his men lifting her spirits, good home-cooked food and better company, or even some headway with her students would be the only things to console her now.


	6. Chapter 6

The rest of Kumiko’s day ended rather flatly. She assisted Ectoplasm in their Maths lesson, contributing only to write up problems on the black board, or answering questions when she was deferred to. She felt like a fraud; not competent enough to teach solo, or enough without a Quirk.

“There you are, Yamaguchi-Kun,” Headmaster Nedzu cried in relief as he approached Kumiko. She was shuffling through upcoming lesson plans and a few files she had dragged up on the individual students she was worried about.

“Nedzu-San,” Kumiko acknowledged, dipping her head respectfully.

“Only your first day here and you’re working so diligently. Yagi-San-“ here Nedzu gestured over his furry shoulder to the blond man (he just kept cropping up, and Kumiko didn’t know what to think of that) “-could only have hoped to be as on top of his work as you.”

Kumiko bit the inside of her cheek, forcing a smile. “It’s a habit I have picked up, I suppose.”

“If you don’t mind,” continued the Headmaster. “Would you be averse to Yagi-San and I showing you to your new lodgings? We have one delicate matter left that you must be informed of, but I thought it might be better to kill the two metaphorical birds.”

Kumiko promptly tidied away her paperwork, knowing that the tiny Headmaster wasn’t going to accept any other answer than ‘Right away, sir.’ ‘Yagi-San’ –the skeletal blond– hovered just behind his employer while Kumiko gathered her things. She did not bother to change out of her tracksuit.

The walk to her temporary accommodation took just over five minutes. Tucked away beside the training grounds (but not too far out from campus that Kumiko would require a bus to pick her up or an hour’s head start), Kumiko had been expecting a tiny prefab shack, or maybe to take up residency in one of the buildings the Heroics students used for simulation training. Instead, what Kumiko found waiting for her was a fully furnished (if a little sparse) home, constructed aesthetically in a traditional style but made up entirely from concrete instead of wood. Where exterior shoji screens would fragilely block out the world, glass screens and patio doors were substituted. A heavy, metallic front door awaited her, and Kumiko would need her Yuuei ID card in order to enter her home away from home.

“This is for me?” she breathed, slipping off her shoes in the entrance and trotted excitedly into the main seating area.

A plush sofa, with an offset coffee table beside it, rested atop an abstractly coloured rug adjacent to an entertainment system. The entire ground floor was of an open plan design. The glass panelling Kumiko had seen from outside her accommodation ran parallel to the living room. Basic kitchen facilities and an area that Kumiko could use to seat herself and eat her meals stretched directly beyond the sofa along the back wall of the house. She couldn’t wait to find out what the rooms were like upstairs if this was the extent Yuuei’s faculty went to.

Nedzu nodded gleefully. “We went to the liberty of purchasing a few things, as well as stocking up the kitchens. We –the staff and I– want you to be as comfortable here at Yuuei as possible, considering that though Aizawa-Kun may be returning soon we would like to keep you on for longer.”

“What do you mean?”

“Aizawa-Kun...” Nedzu sighed. “Aizawa-Kun put himself in a lot of danger taking on as many Villains as he did at USJ. I can understand his reasoning entirely –the safety of his students came before his own. If I authorised it, he would be back here teaching in a heartbeat. He probably believes I am punishing him for acting so rashly, but truthfully, we all just want him to make a full recovery before he returns, and for him to take it easy for a while. Not an easy think for a Hero, if you can believe it.”

“No, no,” Kumiko muttered, “I’ve been in that situation myself.”

Yagi-San, sputtered. “You’ve come to harm before?”

“As concerned as you might be for me,” Kumiko stated levelly, “it was nothing I could not handle. Some students are worth throwing yourself into danger for.”

“But, but you’re-“

“What, exactly, am I Yagi-San?” Kumiko pressed.

“I assumed you were Quirkless, Yamaguchi-San,” Yagi swallowed audibly. “Forgive me if I am wrong in my assumption.”

“Oh no,” Kumiko grinned viciously. “You’re not wrong, it’s just none of your business what I am. I know people who’d kick you to the curb for so much as looking at me the wrong way, and it’s safe to assume that I learnt to defend myself from them.”

Her father, and those under his direct command, were partial to grabbing straight for a katana if Kumiko came home from work distressed. Generally, she was upset because of the toughened airs and actions her students mimicked, and sometimes because of the lacking responsibilities of her fellow teachers. Nothing so problematic that it warranted a pinkie finger being mutilated, but the fact that these men were willing to jump up and fight on her behalf (if only to put a smile on her face too), made Kumiko feel heartened. She wouldn’t be taking over in her grandfather’s stead any time soon because she had no interest in running the Clan. That these men still showered her with their loyalty and respect, despite how she was adamant to remain a teacher, was something else altogether.

“What sort of… company… do you surround yourself with?” said Yagi, stifling a bout of coughing with the gaudy yellow sleeve of his too-big suit jacket.

Kumiko’s mouth clamped shut. She had no erudite excuse for that question, and she’d already said far too much. Yagi seemed more concerned with her safety; entirely dismissing what she'd just said about being able to hold her own. Kumiko felt like ripping the bands holding her pigtails in place out and showing him her right hook. She doubted he'd be worried then. 

“Yamaguchi-Kun’s background is no concern of yours, Yagi-Kun.” The Headmaster had come to her rescue. There would be no fisticuffs... yet. “Though perhaps she might reveal a bit more soon. A secret for a secret, I suppose you could say. That is why we are here after all.”

Kumiko placed her bag –the strap of which she had been clutching tightly for some time now, to the point where her knuckles had lost their healthy flush– on the rug next to her new sofa (hers!) and soundlessly made her way into the kitchen. If stories and secrets were going to be shared, then she might as well play hostess and prepare some tea and light snacks for her guests.

The motions of making tea, of setting fine tea cups onto a tray, and ripping inelegantly through the packaging of some snacks then throwing the latter onto a plate, wasn’t foreign to Kumiko. Her grandfather employed people to cook their meals, or sometimes even his men would dabble in the kitchen – but that did not mean that Kumiko was incompetent. Well, she may have burnt a meal she made for Sawada many moons ago, but that didn’t mean she always cremated the food she cooked!

“Here,” she said gently, handing out the steaming cups and resting the tray on the coffee table. Yagi and the headmaster commandeered the sofa, so Kumiko knelt deftly on her new rug (hers!). The pair muttered their thanks. “What is this secretive business you need to discuss with me?”

Nedzu took a sip of his tea, savouring the flavour. “How well versed are you with Heroes, Yamaguchi-Kun?”

“I know enough, I suppose,” was her response. “I didn’t teach students for them to jump straight into Heroics, as you well know Nedzu-San. I taught them how to be decent people and to work hard.”

“And your efforts have been recognised, I assure you,” the Headmaster agreed. “This year we added a new member to our faculty. You might have heard of him?”

“All Might?” Kumiko frowned. Her eyes, involuntarily, drifted over to Yagi’s tense form. She blinked. The Yakuza liked an impromptu throw-down as much as they liked a well-planned and well-executed hit, and since a tender age Kumiko had been instructed to think on her feet and follow her instincts. What her guts were telling her currently though, was ludicrous. “No way…”


	7. Chapter 7

“Just as I thought.” Nedzu curled his paws around his tea cup tighter. “You’re quick to put the pieces together. Perhaps, had your life taken another route, you would have made a Hero of a frightening calibre.”

Yagi’s – _All Might’s –_ mouth flattened into a grim line. “I wasn’t aware that we were bringing more people into the know, Nedzu-San.”

Kumiko sputtered. This lanky degenerate was Japan’s greatest Hero? Had it been a hallucinogenic substance rather than matcha powder she’d stirred into their tea? Were the Yuuei staff corrupt from within, and more importantly, did Kumiko have to take the law in her own hands and blow her lovely new apartment to kingdom come to halt the building’s stint as a drugs warehouse?

Because she would.

She knew a man who could supply her with some goods by the by, and if they couldn’t deliver then there was always the old-fashioned route.

A few pieces of sharpened flint and some tinder could always get you out of trouble. Kumiko always made sure to pack them in her bag no matter where she was going, along with her keys, purse, extra underwear, and her phone(s). The emergency fire-starting kit was nestled between Kumiko’s collection of zip ties and her trusty taser (used only when her fists felt tender or if she didn’t think some jumped up little thug was worth the effort).

“You can’t be him,” Kumiko stammered. “You’re all – you’re all _you!_ ”

Nedzu’s little beady eyes glinted with mischief as her turned to Yagi. He wiggled his brows. (Did rats and bears have brows? Kumiko wondered. Or did they just have fine, eyebrow-like whiskers like cats did?) “Do _the thing_ , if you wouldn’t mind Yagi-Kun.”

Kumiko watched as Yagi released a sigh of one who had long-suffered, then grimaced when the man clenched. It was like watching a magic trick; one minute, lanky Yagi was there, and the next there was All Might. Poof. Flash of smoke and Yagi was gone. Simple substitution. Kumiko dropped to her side, checking beneath the couch in case Yagi and the Headmaster were playing a trick on her. The fact that All Might now filled out Yagi’s unorthodox choice in suits (rather snuggly, Kumiko thought and caught herself ogling), had nothing to do with it.

This had to be one big elaborate joke; hazing the new teacher or something, right?

“I can assure you that we aren’t pulling your leg, Yamaguchi-San.”

“But Yagi- and the, _All Might –_ and-“ Kumiko felt dizzy. She rolled onto her back, clasping her hands over her stomach and staring blankly up at the ceiling.

“Oh dear,” hummed Nedzu. “Still, thank you for sharing your secret to practically stranger, Yagi-Kun. I know how you like to keep your identity secret. Yamaguchi-Kun’s knowledge of this may help us in the long run, however.”

“How so?” boomed All Might’s voice. Kumiko’s lips drew back in a faint, mortified screech.

“Yamaguch-Kun, and her… family… have connections we don’t. Connections to people not even Tsukauchi-Kun has at hand.” Nedzu drained the rest of his tea from his cup. “Unsavoury connections you might think, considering not even Tsukauchi can place an agent within their ranks.”

“We don’t take to strangers,” Kumiko growled, finally recovering her senses. “And we sure as hell don’t squeal to the fuzz on each other. Family businesses have to stick together, and all that,” she added nonchalantly.

“Yakuza?” All Mi- _Yagi_ , gaped. “You’ve got a criminal teaching young, impressionable, students?”

“I think Yamaguchi-Kun would personally take offence to that, Yagi-Kun,” said Nedzu, carefully eyeing Kumiko’s fists as she clenched and relaxed them a couple of times.

“Those ‘criminals’, as you so put it,” Kumiko bit through gritted teeth, “raised me when my parents died, and have supported my dream of becoming a teacher despite the fact that there is no one left to take over as the Head once my grandfather passes. I do not want the position – I never will, and I’m not right for it anyway. We’ve bled together, broke our fast together, shared memories and secrets with one another, and I will not allow you to tarnish their natures in such a fashion.”

All Might looked as he’d downed a spoonful of sherbet. “My apologies.”

“Any way,” Kumiko huffed, letting the former subject slide for now. “How did you end up so beat up when this form is buff?”

“Oh,” Yagi said sheepishly, and with another cloud of smoke All Might was gone. The baggy mustard-coloured suit remained though, and the emaciated man wearing it originally returned. “Super Villain got a lucky hit in.” Yagi patted his stomach, flinching slightly. “I don’t… can’t eat a lot now, and my muscle form and powers are fading. Eventually, All Might will be a thing of the past, but I have one last thing to accomplish before I’m gone.”

Kumiko’s fingers curled into her leg; pinching at the red jersey fabric of her jogging bottoms. “And that is?”

“I need to return the favour,” All Might admitted, a hand resting just over the left side of his rib cage.

**Notes for the Chapter:**

> I'm baaaack.... and will likely be gone again for four months!
> 
> To everyone who's been reading _Substitution_ so far, thank you so much! This was just an off-the-cuff idea I had and wrote down, so I really didn't think anyone would pick it up. 
> 
> Chapter Seven was just waiting there in my documents for an age, and I've now run out of prepared chapters. Currently I'm in the middle of my MA so my time is going towards that and not writing. Not entirely sure when the next update will be, but thank you so much for your patience and support. 
> 
> Come natter with me [here!](https://yuilhan-writes-things.tumblr.com/)


	8. Chapter 8

If Kumiko’s enthusiasm and zest for life had dimmed a little overnight, and if questioned on her behaviour, she’d chalk it up to eating dodgy tempura and not the fact that Japan’s Symbol of Peace had told her he wanted to find his arch nemesis and finish things once and for all.

For someone who’d looked distastefully at her when Kumiko’s heritage had been announced, Yagi was no better, and he certainly couldn't claim the moral high ground this time. He wanted to find the man who’d killed his mentor—the same man who had tried to kill him off only years prior—but he turned up his nose at the Yakuza, who made corpses come and go like they were part of an elaborate magic trick.

Those were the good old days, Kumiko thought. Since the Ooedo household had needed to be ‘child-friendly’ when her Grandfather had taken Kumiko in, no skeletons remained in the closets (so to speak). Disposed of discreetly like Tuesday’s recycling, sure, but the Ooedo’s principles changed accordingly towards relaxed working hours, a family environment, and not bringing your work home with you and leaving it to bleed out in the front hallway while you went through the motions of domesticity. 

Kumiko shuffled her way through the next few weeks in a daze. The students were oblivious as always, but she could feel something building. Maybe she had it the wrong way around, and the students were building something she was oblivious too? There was the unmistakable feeling that she was missing something crucial, but Kumiko was too preoccupied with unravelling Yagi’s character to pay attention.

Well, perhaps that sounded too negligent. Kumiko was a diligent teacher; she catered to her students needs, even if she had to bend over backwards and go out of her way to do so. No lesson, if it was learned well, need be deemed impossible to teach. Her students depended on her for guidance, and guidance she would provide.

However, these sorts of ground-breaking life lessons could be waiting in the wings for weeks on end. If you had students who didn’t want to learn—who didn’t want to change, mature, and expand their horizons just a little—then the lesson one wanted to instil wouldn’t hold. Kumiko was patient. Kumiko could wait. For the time being she watched the fractures in Class 1-A expand and contract; saw how things could heal, and how new wounds were made.

Midoriya was a contradictory dithering-yet-determined wreck. Bakugou was nothing Kumiko couldn’t handle; she’d seen his jumped up little punk act countless times throughout the years, and she knew that beneath it all there was a heart of gold. Perhaps not in the sense of what some might call ‘innocence’, but an ability to always do good in the world despite rough mannerism’s keeping altruism at bay. There was another worrying concern though. One that made Kumiko want to bang her head into a wall, uncaring about the damage she’d ultimately cause if she went all out.

Todoroki Shoto.

From money, Kumiko had noticed at a glance when making her impressions of Class 1-A shortly after gaining her temporary post. Mainly used ice formed on the right side of his body in the spars she and All Might oversaw. Again, not the weirdest thing she’d ever seen; sometimes Quirks just didn’t manifest properly. Some people lamented that they didn’t have useful enough Quirks to work in the Heroics industry, but if Todoroki was confident in working with what others might call an incomplete defence (and if he had the power to back it up), then good for him.

No, it was the little things that Kumiko noticed which concerned her. Other than Yaoyorozu Momo, who Kumiko believed was a family acquaintance and familiar with Todoroki from the student recommendation system Yuuei had in place, Todoroki Shoto was isolated. Perhaps due to who his father was. Couldn’t be easy being Endeavour’s son.

Kumiko compiled her thoughts on the boy’s character, and the standard tells of a dysfunctional homelife (celebrity parents and all that jazz) were soon swallowed under a wave of fierce concern. Todoroki Shoto was fastidiously controlled; as unmoving as the ice that encased his side when using his Quirk. He held his left side stiffer though, like there was no sensation there. Like he _wanted_ there to be no life in that side of his body. Some days his whole body was stiff, as though he’d not stretched and cooled down sufficiently before and after sparring, despite not having classes covering physical aspects of Heroics the day before. Then one day he’d slipped. Itched at his arm when he thought no one was looking, which bunched up his uniform and exposed the bruises.

Todoroki was prickly. Isolated. Scarred. Scared. Reluctant to form bonds with people who aught to be his Nakama. Maybe it was presumptive of her to cast judgement on what Todoroki’s past and homelife might be like, but Kumiko didn’t like what her gut was telling her. Unfortunately, unless she somehow wrestled him to the safety of her family home, Kumiko could not intervene freely. She promised Aizawa that she’d look out for his students, and if observing and protecting from the shadows was all Kumiko could do for the moment, she’d damn well do her best at that!

She’d smacked her head into the glossy lacquer of her desk for the fourth time in a row before Yagi (also present in the staff room) finally asked her what was up.

“I’ve got a problem, but I can’t legally solve it,” she replied forlornly. “Too much red tape, and I’m sure if the Pigs start snuffling around everything will just be swept under the mat.”

Yagi, in his deflated form, smiled at her grimly. He was getting used to her unique terms and phrases (Kumiko passed it off as being a fan of Yakuza movies if she slipped around the rest of the faculty not in the know). “I’m sure you have means of sorting it illegally.” Kumiko shook her head. “Not even bending the rules a little?”

She shook her head once more. While a little offended that he’d suggested she make use of her family’s… oddities… yes, there were means — usually whisking the aggrieved party away from danger, hiding them from harm, and, if they wanted to, allowing them to join the family (or at granting them the Ooedo Clan’s protection). But Kumiko would have to do things properly this time. Especially if her suspicions were correct. Especially if she wanted to keep the scandals to a minimum. She didn’t need a repeat of her last teaching gig.

Kumiko tilted her head to the side in thought, and Yagi, sensing that she was not going to be more forthcoming with this topic, excused himself. She could hear him faintly coughing in the corner by the water cooler; the sound wet and heavy. There was the unmistakeable sound of tissues rustling with use, being crumpled, and then dumped into the waste bin.

So, she couldn’t do things legally. She also couldn’t take illegal action. Kumiko would have to bide her time _again_. She slammed her head into her desk once more, this time dislodging a stack of papers nearby. They fluttered over her head; burying her neck and shoulders too. Gingerly extracting herself from the pile, Kumiko blinked one. Twice.

Out of the pile had slipped the card which Nedzu had pushed across the table to her when they first met. The contact details to Sawada Shin’s office were swiftly snatched up into her eager hands, and Kumiko whooped with joy—stopping short of gleefully kissing Sawada’s business card.

Sawada Shin had been one of the most intelligent students Kumiko had ever taught. Cold and aloof, he was usually one step ahead of his peers (which had earned him the right to be the leader of _his_ (Kumiko’s first) Class 3-D). He also took great pleasure in blindsiding Kumiko. Really, the age gap was a point of contention, yet Sawada had still insisted he loved her.

In a way, Kumiko loved him too. He was her precious student. Part of the first group of students she had ever taught and set out onto the straight and narrow path of adulthood. There was a special place in her heart for all of the original 3-D students. Kuma, who Kumiko had kept in contact with the most, was such a respectable man now. He and his wife were experiencing the joys of parenthood, and his ramen restaurant was always full to the rafters. And she loved him for that. Loved that she had been able to help Kuma find his path.

Her love for Shi- _Sawada._ Sawada. Shin would be too familiar, too intimate, and teachers weren’t supposed to be _intimate_ with their students. Those kinds of relationships were complicated and destined to result in hurt and a criminal conviction. Still, she knew that if she should ever need his assistance, Sawada Shin would have her back. An extensive knowledge of the Law, the brains to wrangle the best outcome for even the direst of situations, and his connections to the police made Sawada a precious ally.

Kumiko ran her fingertip over his name, the characters printed in stark black ink onto glossy white card. She would ring him later. Ask him to do some covert digging. If Kumiko couldn’t rumble the Todoroki’s household without a solid case behind her and had to play the waiting game, there was no reason she couldn’t gather what she needed first. She never ran into a fist fight unprepared, therefore a legal fight would work in the same way, right? 

“I think I might have found a way.” She grinned enthusiastically at Yagi.

“That’s nice I guess, but we’ve got other things to think about.”

Taken aback, Kumiko timidly asked, “Like what?”

Yagi seated himself back at his desk and dropped his head into his hands. His fingers looked as fragile as fine china as they rubbed and probed at the tension in his temples. “Like the fact that the Sports Festival is coming up and Midoriya is likely going to explode his arm off again.”

The Yuuei Sports Festival was a well-known event. That was what Kumiko had been missing, she realised. She’d been present in the meeting when Nedzu announced the added security measures to the event in the wake of the attack on USJ, but it had slipped her mind after informing Class 1-A they had two weeks to prepare. If Yagi was right and Midoriya was going to-

“What _what?”_

**Notes for the Chapter:**

> Two updates in the last week? Is the world ending?   
> (Nope, I just needed a break from essays.)
> 
> I'm going to have a well-deserved nap now.


	9. Chapter 9

Midoriya did not, in fact, ‘explode his arm off again’, but Kumiko couldn’t help but grind her teeth together whenever she saw the boy’s bandages. Her concerns about Todoroki had been well founded, with Midoriya omitting the truth behind his excessive punch out with the dual-Quirked boy and Kumiko quickly filling in the blanks. While the boy’s arm was ‘fractured to smithereens’, which didn’t quite equate to combustion, how long would it be before Midoriya’s body ultimately shattered due to his bleeding heart?

Kumiko wasn’t impressed either way, despite Midoriya making a pleasant impact on Todoroki’s abrupt ( _toxic_ , Kumiko amended. It was toxic and so very very hurtful for the child) way of thinking.

Kumiko rubbed at her stomach listlessly. She wanted comfort, and to run home to her grandfather and the family, and to eat Kuma’s ramen like she did when she needed cheering up, and to not feel like a stilted, unresponsive teacher who couldn’t act on her concerns because of Heroic and Governmental red tape binding away the fact that Japan’s second-ranked Pro Hero abused his kids. Possibly _kids_ , **plural**.

She scowled and cracked her knuckles. The mug in her hands with lukewarm tea inside trembled like a fragile bird in her grasp. A crackle in the glaze which protected the mug’s delicately painted swallow pattern fractured a little further.

It was an hour before Kumiko was due into work, and she sat curled up in a slouchy arm chair with a drink she had fixed in her home-from-home with the belief that it might make her go through the motions of being a pleasantly mannered, conductive member of society, and not someone who wanted to kick another person’s teeth in. The kids didn't need to see that side of her just yet. Tea was a supposed cure-all, but somehow it didn’t quite quell Kumiko’s (violently) protective instincts.    

Kumiko’s urge to curb stomp someone had never been this strong before, and she wasn’t sure if her family would be proud or somewhat horrified of her indulging said urge. Perhaps, she thought, it would be an exquisite concoction of both. Her grandfather’s men had grown up with her monstrous strength. They had taught her the right and multiple ways of political and physical warfare, what with varied escapades landing some of the family in hot water with the police and occasional spats with other ‘families’ needing Kumiko’s right hook for reinforcement. They had all tried to keep her involvement at a minimum though, because as violent as they might be Kumiko's family respected her choices.

Midoriya would have made a decent Yakuza, thought Kumiko. He was loyal. He was willing to do anything to help those he considered redeeming —even more so if he saw them as a friend— at the expense of his own personal safety. Kumiko saw a little bit of herself in the boy, but that didn’t mean she _liked_ what she saw.

Kumiko Yamaguchi would do anything for her precious students. Children had to learn, after all, and what better way to do that than with a teacher who would shield and nurture them into adulthood? However, watching children tear themselves apart wasn’t in a teacher's job description, even for teachers of burgeoning young Heroes.

Later that afternoon, Kumiko had sat in on Recovery Girl’s talk with Midoriya and had nodded vehemently in agreement that he should cause no further damage to his arm. The boy’s eyes had dimmed a little, and a stubborn set to his mouth told Kumiko that if the need ever arose, Izuku Midoriya would destroy himself if he could save another. She hated it, and Yagi just sat there when she confronted him in the staff room about Midoriya’s behaviour. Yagi's apathy was strange considering he’d been the one to alert her to that to begin with, so Kumiko hopped onto the next bus heading to the hospital once her paperwork was done to pay Aizawa a visit.

It wasn’t that Aizawa was laughing in her face (he totally was), but Izuku Midoriya was one student that Class 1-A’s teacher fondly (or so Kumiko believed) thought of as a ‘problem child’. Kumiko knew that Shouta Aizawa could be abrasive. His method of teaching was cutthroat to some —preferring to leave the children in his care to flounder if they didn’t demonstrate even a glimmer of potential— but Kumiko could sympathise. Heroics was a profession one had to be dedicated to. At times, being a Hero came before your family, your significant other, even yourself. To even continue to instruct a student who couldn’t grasp the gravity of what they had signed up for would be to waste your time. Time better spend educating those who did understand.

Kumiko sympathised, but she had also experienced the alternative. She took on teaching jobs for hopeless cases. She reformed those her colleagues deemed irredeemable. And those kids had _thrived_. Still, she was glad Aizawa could laugh about her predicament. He looked like he needed to smile more. Maybe if he smiled more his grin would become more natural and less maniacal?

Eventually the teacher sobered from his dark chuckling. “You’ve got to stop him from doing this again.”

“How can I?” Kumiko queried. She wasn’t in charge of their Quirk training, and Midoriya was the epitome of a well-meaning loose cannon.

She couldn’t see Aizawa’s baleful glare, for his head was still wrapped loosely in soft bandages to minimise the chance of overstimulating his eyes, but she sure as hell felt it. “I was an Underground Pro before I became a teacher. I’ve seen and know a lot of things. _People_. Specific organisations… I also know how to dig deeper than average Heroes for information others would prefer to leave buried in the past.”

Kumiko fiddled with the hem of her skirt. The plastic chair she sat in creaked as she lent forwards slightly. Across the hall in another private room, a patient coughed. Kumiko inhaled. A few seconds later, she exhaled. Her hands clenched into fists atop her thighs; her knuckles popping softly. The mug she had held hours earlier would have shattered under the pressure.

“I think you’re more than capable of knocking some sense into my kids, ‘Yankumi’.”

“You know,” Kumiko intoned flatly. Aizawa said nothing. “Fine. It’s not as if this was a permanent post anyway. Of course, everything I’ve done before has to come back to bite me in the end. Thank you for your time, Aizawa-San.”

Kumiko forwent the bus ride home. She wandered through the city, tempted to remove her heels and run run _run_ if only to do something that might clear her head. But she knew that it wouldn’t help. Running was reserved for speeding to the rescue and away from attractive men who flustered her, not for trying to escape your problems.

She had time before Aizawa’s leave ended. He had a few more weeks in the hospital at best, and then a further fortnight at home to rest and recuperate his physical strength (perhaps a little longer, if Aizawa wanted to return in top form), but after that, Kumiko would be out of a job. She had just over a month to make a difference —less, even, because the kids were out on internships for a week. Then there were exams and training camps to factor in.

At the expense of besmirching her reputation as a teacher, and never again being able to take a teaching post if she was ‘let go’ from Yuuei of all places (one of the most prestigious schools in Japan, if not the world), could Kumiko really help shape these students into model Heroes?

She didn’t know, and while she was afraid to lose her livelihood, she was more than willing to give it a shot.

**Notes for the Chapter:**

> I liiiiiiiive. Sort of.
> 
> Currently in the middle of writing my dissertation. Needed a break. I really want to finish this story, so the short chapters are useful in keeping me motivated and willing to write. Apologies if there's any errors.
> 
> Thank you for all the support! 
> 
> In the meantime, come natter with me [here on my Tumblr!](https://yuilhan-writes-things.tumblr.com/)


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